Org-roam
Org-roam is a plain-text personal knowledge management system inspired by Roam.
It is built on top of Org-mode and thus offers all of its features as well as
bidirectional linking, graph visualization (via org-roam-ui), tagging and
searching.
org-roam-ui
org-roam-ui is an emacs package that starts a local web server to serve a frontend for exploring the org-roam database. It's designed to run on localhost, but there have been attempts to publish it